1. Field of the Invention
The present invention relates to a computing device, and more particularly, to a computing device with an improved start-up performance.
2. Related Art
Computer platforms are implemented in a range of electronic devices, such as portable electronic devices including portable computers, mobile interne devices, smart phones and the like. Computing platforms are also being implemented in vehicles to control a range of vehicle functions. Applications, such as vehicles and other devices that use computing platforms, may use as a computing platform, for example, the Intel® Centrino® Atom™ platform using an Intel® Atom™ processor, which is also termed Menlow or Menlow XL platform.
Applications typically require that the computing platform start up and operate quickly to minimize the delay before the applications can be used. Automotive applications require particularly fast start-up times to make the vehicle functions controlled by the computing device available as soon as the vehicle is started. For example, the warning sound for reversing the vehicle should become available immediately after starting the vehicle. Further, there may be special requirements regarding early audio and early video, for example.
When a computing device is started up, a reset signal is generally applied to the central processing unit. When a synchronous reset is used, as is used in the Intel® Centrino® platform, the reset signal requires a clock signal for recognition and processing by the CPU. The clock signal is typically generated by a real-time clock (RTC), which may use, for example, a 32 kHz quartz oscillator. Such quartz oscillators may have an oscillation build-up time of 800 ms or more. The CPU cannot process the reset signal before this build-up time elapses. Therefore, the reset signal is held and is not deactivated until the build-up time elapses. If the reset signal is deactivated before a valid RTC clock signal is available to the computing device, the computing device may exhibit undefined or erratic behavior. To ensure that the RTC clock signal is not deactivated too soon, an additional delay is introduced in the start-up phase of the computing device. The added delay and the delay caused by the initial program load (IPL) and the start-up application via the relatively slow low pin count (LPC) bus may result in a delay at start-up of such a conventional computing device that can no longer meet the requirements of automotive environments.
A computing system based on such a platform generally requires about two seconds for starting up and loads a system application having a size of about two megabytes (MB) during the booting procedure (IPL). A delay of such length before the computing device becomes operable is generally too long for automotive applications.
Accordingly, there is a need for improving the start-up performance of a computing device. In particular, it is desirable to reduce the time required by the computing device to become operational.